Risk stratification in pulmonary arterial hypertension (PAH) using multiple parameters is necessary in order to apply modern treatment algorithms and improve clinical outcomes in these patients. Upfront double oral combination therapy is recommended for the majority of low- and intermediate-risk patients, while upfront triple combination therapy, including a parenteral prostacyclin is recommended for high-risk patients. However, a satisfactory clinical response is unacceptably low, occurring in only 39% of the combination arm even in the context of a randomized clinical trial (AMBITION). A future challenge is to apply more precise risk stratification strategy, potentially including parameters of right ventricular function, which might guide more individualized treatment decisions.